Valve structure



Jan. 24, 1939. c, E, gE sT 2,145;20s

VALVE STRUCTURE Filed Nov. 12, 1936 I INVENTOR Car/ 5 Berrf/er ATTORNEY Patented Jan. 24, 1939 UNITED STATES PATENT OFFICE VALVE STRUCTURE Carl E. Berstler, Reading,

Pa., assignor of Weinerth, Reading, Pa.

Application November 12, 1936, Serial No. 110,453

6 Claims.

My invention relates to valve structures, and particularly to valve devices for internal combustion engines, as employed in automobiles.

In engines of the above-indicated character, as heretofore constructed, trouble occurs at the valve structures, caused by sustained heat, by the form and relation of the valve heads, stems and seats, and by other factors.

Burning, pitting and warpage of the valves and cooperating members cause gas leakage and premature explosions, with consequent loss of pickup, power and efficiency, as well as the delay, inconvenience and loss from repairing the damage thus caused.

The valve heads and stems generally employed, so far as I am aware, have been constructed with the connecting portions between the heads and the stems below the lines or planes of the head seats on the blocks of vertical engines in the closed positions of the valves, or so close to these planes that the heads are ex cessively heated and tend to warp away from the valve seats and radially and axially inwardly toward the valve ports.

Among former valves, are those having heads in the form of flat discs, whereby the pull of the stem, and the reaction of the valve-block seat, under the valve seating action, tends to directly cause the head to collapse. A valve of this character has heretofore been provided with a tubular valve-seating portion projecting along the stem, but this does not avoid the collapsing tendency.

A valve of another prior form, although of arched contour, is so constructed that the lateral component forces of the pull of the stem, are imposed directly against the valve and block seats, whereby the head spreads readily under the heat of service, and feather edges rapidly deteriorate, so that even a head of this character, having an arch, easily collapses.

Feathered edges of the valve heads become excessively hot, so that they are soon damaged from this cause and contribute to the warping above mentioned.

At the position of connection between an ordinary valve head and its stem, there is a relatively massive body of metal defined by a fillet of large radius between the underside of the head and the upper side surface of the stem, which is disposed close to the valve seat on the block. This feature also conduces to excessive heating of the head and the seat, so that the cumulative eifect of the features mentioned renders the members short lived, and requires them 7 to be frequently adjusted, repaired or renewed.

By'reason of the shape and relation of the valve heads and stems to the engine block valve seats, portions of the peripheral seats of the heads tend to lift oil the block seats, thereby causing leakage and burning, and pitting of the valve head and block seats, resulting in. the necessity of frequent valve grinding.

The outer peripheries of valve heads heretofore constructed also overhang the block seats in such manner as not to be cooled by the block and thereby becoming excessively hot, which further adds to the early warping and destruction of the heads.

With the heads flat, concave or otherwise improperly shaped on the top, back pressure-decreases the efficiency of the valves, robs the. engines of balance and power, and causes vibration. Also, with straight line surfaces, edges and other configurations, the heads cause undue turbulence of the gases.

When the stems or stem seats are off center, or become so from use by reason of the. shapes and relations of the heads and the stems or from other causes, the eccentricity between the valve heads and the seats causes gas leakage, loss of power and early damage to, or destruction of, the valve members.

Other factors contribute to the rapid loss of efliciency, even of engines skillfully made of the best materials, so that the valves have been the subject of much research.

Among the general objects of my invention are to overcome the trouble, expense and other disadvantages above indicated and to provide a valve that'shall endure in effective condition for a long period of time without attention; without added expense in manufacture and assembly, and that shall conserve gas, render the engine smoother in operation and have many other advantages.

Specifically, and particularly in connection with an internal combustion engine, an object is to so form the connection between the head and the stem of a valve, and to place it above or near the plane of the seat in a vertical engine, or corresponding position in an engine of other position, as to materially reduce heating of the head.

Another object of the invention is to have the forcesof the pull of the stem, and the reaction of the valve and blockseats, so directed substantially parallel to the stem along a substantially tubular valve-seating skirt in a trussed valve having the skirt in addition to, or independently of, the truss, as to substantially preclude spread of the head by preventing the application of the outward forces of the truss directly on the valve and block seats.

Another object is to render a valve head free from feather edges, or in other words, that shall have its surfaces extending around the valve seat at not substantially less than a right angle to its seat engaging surface.

Another object is to provide a true streamline valve head whereby to reduce turbulence of the gases passing through the valve and to render such head more nearly free from back pressure than valves heretofore employed.

Another object is to provide .a valve head that is trussed or braced against its pressure on the seat, that is free from outward .overhang, that seats more effectively, that retains its ability to seat properly over a longer period of time in service, that is self centering, that is more flex.- ible, that seals better against the block seat and that has other advantages.

To render the invention more clearly understood, means are shown in the accompanying drawing for carrying the same into practical effect, withopt limiting the improvements in the useful applications thereof to the particular structures which are given by way of example and may be modified as to shape, relation, texture and other features without departing from the nature and scope of the invention as set forth and claimed.

In the drawing:

Figure 1 is a view, partially in vertical-plane section and partially in side elevation, of so much of a vertical-block automotive engine as necessary to illustrate a valve structure substantially of the mushroom type constructed inaccordance with the invention, also shown in the figure;

Fig. 2 is an enlarged detail view of the upper portion of thestructure as viewed in Fig. 1;

Fig. 3 is a viewsimilar to Fig. 2, but on a reduced scale, of the invention in modified form;

, Fig. 4 is a view similar to Fig. 3 of the invention in another modified form; and

Fig, 5 is a view similar to Fig. 4 of the invention ina further modified form.

In practicing the invention a vertical poppet valve with the head at ,the top of the stem, the head is connected to the stem above the line or .plane .of its peripheral seat or not substantially lower than this plane.

In a valve positioned other thanvertically, the

relations will be the same as though the valve hadbeen constructed vertically and placed in the desired position, such as the diagonal position in an engine of the V-typeor an inverted position an engine of theradial type. Thus the position of oonnectionbetween the head and thestem in any engine may be stated as substantially no farthey toward the valve seat, in the closing direction of the valve, than the fartherinost plane of the seat in said direction. The structure provides a recess in the head around the stem, the inner diameter of which is substantially equal to the diameter of the stem. r By,this feature alone, that is irrespective of the shape or size of the connection, to a certain extent, a portion of .the valve ordinarily attracting intense heat is spaced farther. from the usual position causing such heating.

The connection between the head and the stem .being positioned as above set forth, it may also, according to the invention, be of such shapeand size as to augment the cooling effect or to rein force the connection without unduly interfering with the effect. This result is accomplished, in

the example given, by removing the usual fillet of large radius between the head and the stem, and connecting the stem directly to the head or by a fillet of substantially reduced radius. The mass of the material opposite the valve seat is thereby reduced and spaced farther from the seat.

Also, in the example given, the inner and outer surfaces of the head adjacent to, and at opposite sides of, the seat engaging surface thereof extend from the seat engaging surface at such angle thereto as to avoid feather edges. Angles satisfying this condition to greater or less degrees may range from slightly less than a right angle to an obtuse angle of any desired degree; A true right angle is a practical angle to produce the desired effect but departures may be made within the spirit of the invention. That is, an angle less than a right angle, if not too acute,

although forming an edge which may approach the ideal conditions, will subject the head to less heating than a more acute angle, or the angle may be obtuse and obtain the advantages of the feature.

The head is arched or of smooth rounded dome shape rendering it of true streamline contour whereby to cause the gases to fiow smoothly without turbulence or back pressure. This feature also provides the head with a truss bracing effect against its pressure on the seat with respect to which it is also shaped to prevent peripheral portions of thehead from lifting off the block seat, as in a fiat or other non-trussed head.

The block seat, in the example of the invention given, is larger in diameter than the head such that any expansion of the head is permitted to occur without opposition by the block and overhang of the head relative to the outer periphery of the block seat is eliminated. This overhang is commonly provided in ordinary valves to allow for frequent grinding which the valve hereof does not require.

With the truss construction hereinbefore set forth and a slightly frusto-conical seat engaging portion, a self centering action is provided which ,7

tends to maintain the head and the stem in accurately centered position irrespective of slight manufacturing or assembly discrepancies or of effects in service tending to throw the head off center, and prevents lifting or warping of portions of the valve head off the block seat.

An important feature of the invention resides in the provision, in combination with a trussed valve head portion, of a valve-seating skirt on the fiexible and to cause the head to provide more effective closure or sealing action against the cooperating seating portions of the block, one or both of these seats may be provided with a groove between its inner and outer peripheries. This feature is produced for the first time, so far as I amaware, in a valve head seat, or in its companion seat on the block, or in both seats, wherein the valve head is trussed and has a tubular valve-seating portion or skirt extending, along :the stem. This feature rendersthe head or the 1 block seat more flexible, brings the seats more firmly and evenly together and provides a more efiective seal.

Referring to Fig. 1, the device comprises, in general, a valve head 1, a stem 8, on which the head is disposed, a valve block seat H], on an engine block portion I2, a valve guide around the stem and press fitted into a portion I 6 of the block, a flange l1 at the bottom of the guide [5 against a portion N3 of the block, a disk-like valve spring keeper held around a lower portion of the stem by a valve spring keeper pin 2|, and a spring 22 around the stem 8 between the guide flange I! and the keeper 20.

Referring also to Fig. 2, the valve head I and the stem 8, in the example given, are of material, such as silichrome steel, formed as one homo geneously integral member, with the stem of uniform cylindrical shape, although they may be of other material and shape.

The stem, which is vertical in this instance, and operable from below, projects through the port 14, and through the opening in the block member on which the valve seat Ill is-disposed, to a position beyond the member or the seat at which it joins the head. This position of joinder between the stem and the seat is thus above the lower, upper and intermediate planes of the seat l0 whereby maximum clearance is provided along any radius in these planes.

The head is of smooth rounded dome shape having the greater portion of its outer transverse surface 24 farthest from the'stem arched in longitudinal section, or in any plane parallel to, and through, the longitudinal axis of the stem toward the seat, of relatively great radius from a point substantially on the stem axis. However, the outer peripheral extremities of the surface 24, join, or merge into, a surface 25 of relatively short radius, generally in any of said planes, from a point inside the arc of the surface 24, so that the outer surface portions 24 and 25 are one continuous stream-line surface. The inner transverse surface of the head also has portions 26 and 21 conforming to or following the surfaces 24 and 25, respectively, whereby to define a truss, or render the head of truss-like character, having its outermost portions between the surfaces 25 and 21, approaching parallelism to the stem 8, and extending substantially normal to the sloping valve seat surface In. Thus, the head is so strongly braced against warping lift of any arcuate portion of its periphery that to effect any such lift would first require cracking of the head through the middle, which is practically impossible with the truss shape shown and the heat and valve pressure forces involved.

If a line of the head 1 (Fig. 2), were extended beyond the outer limits of the head, it would pass through a position above a valve-seat surface 29, whereby the valve head forces are not imposed on the surfaces l0 and 29, but are converted into forces extending along, or substantially parallel to, the stem.

Thus, the head may be defined as having a contour extending successively from its center or topmost point, along an arch 24 on the outer head surface toward the outer periphery of the head and the other end of the stern, along an outer surface portion 25-29, including the portion 29 sloping toward said other end of the stem along a valve-seating surface, and along a surface represented by lines 2'l-26 extending radially inwardly and toward said one end of the stem on the inner surface of the head to the stem, in which the inner surface cooperates with the outer surface represented by the line 24, to define an arch,

and the inner surface represented by the line 21 cooperates with a portion of the outer surface represented by the line 25 and the line 29 to define a substantially tubular portion, in addition to said arch.

The surfaces 25 and 21, in the example of the invention given, are at substantially right angles to the surface 29 therebetween engaging the seat l0, whereby feather edging is avoided between the surface 29 and either of the surfaces 25 and 21.

- This feature, by eliminating thin marginal edges,

avoids undue heating of the peripheral edges of the valve head at opposite ends of a radial line along the surface 29, places the valve head seat portion closer to, and seats it better on, the cooled block seat and thereby further aids in avoiding warpage of the head. The surfaces 25 and 21 are not necessarily curved, or curved about the same radial center, so long as they fulfill the general requirements of lines that are so curved or equivalently formed to produce like results. Likewise, the inner and outer main transverse surfaces of the head need notnecessarily be curved, or curved about the same radial center so long as like results are obtained.

With the surfaces of the head thus formed and located, substantially free from non-stream-line features, the gases flow around the head in a smooth eddyless stream or, in other words, are

directed to avoid back pressure and excessive turbulence. This feature allows the gases to pass the head in more rapid, full and complete manner to ensure more effective production of uniform balanced power, to maintain pick up, to avoid vibration and to improve the operation of the valve generally.

Also, with the head formed convexly to the seat at each of its inner and outer surfaces as set I forth, the truss effect thereby given against the action of the valve on the frusto-conical seat it ensures more accurate seating tending to center the head and stem. In an ordinary valve, the

head tends to contract radially inwardly-and to 4 collapse into the port It.

The inner surface 25 of the head merges into the upper side surface of the stem 8 through the surface of a fillet 32 of short radius whereby to avoid undue radial thickness of the stem at this position near the line or plane of the seat Hi. This feature avoids the use of a large mass of metal located close to the seat, as in an ordinary valve having a flat or other head joined to the stem by a fillet of large radius and thereby avoids heat maintenance or storage in the parts near the seats on the head and block which receive maximum cooling and are maintained in accurately fitting relation over long periods of time.

In Figs. 3, 4 and 5, parts corresponding to parts of the structure of Figs. 1 and 2, are designated by corresponding reference numerals and letters of the alphabet suffixed thereto.

Referring to Fig. 3, a head la differs from the head I of Figs. 1 and 2 in having an annular groove 34a in its seat surface 2% between its inner and outer peripheral surfaces 2'50. and 25a whereby to render it more flexible for closely accurateseating against the seat Ella and more effectively sealing the valve. In this structure also, the stem is connected directly to the head with little or no fillet at the position 32a.

Referring to Fig. 4, a groove 34b is disposed between the inner and outer peripheries of a seat [0b to similarly render the seat more flexible for accurate seating on the head. Surfaces 25b and 21b corresponding to the surfaces 25 and 21, respectively, are each disposed at a slightly obtuse angle to the line of a seat surface 291). This feature illustrates another way of rendering the seat engaging head edges free from acute angles or feather edge construction.

Also, in this form, a stem 81) is joined to the head lb through a constricted stub stem portion 3lb to further enhance the cooling effect.

In the structure of Fig. 5, each of the seats is provided with a peripheral groove; a head 1c having a groove 340 in a seat surface 290 between its inner and outer peripheral surfaces 210 and 250, respectively, and a seat Hie having a groove 350 between its inner and outer peripheries.

In the latter form, the surface 250 is only slightly less than a right angle to the line of the surface 290, whereby to approach the non-feather edge character of the previously-described structures.

The seat of each of the heads I, la, lb and lo, and each of the diagonal or frusto-conical seats l0, Illa, b and IE0, lies on a line in any radial plane parallel to, and through, the axis of the corresponding valve extending in only one general direction, in contradistinction to a valve embodying a seat having surfaces extending along lines at an angle to each other in such plane.

Also, in the structure of Fig. 5, a stem 80 merges into a stub portion 320 of slightly larger diameter next to the head 10 to provide reinforcement, without the disadvantages of a fillet of large radius.

Although I have shown and described my invention in particular forms changes may be made therein, without departing from the spirit and scope thereof, as set forth in the specification and claims.

I claim as my invention:

1. An internal combustion'engine valve comprising a stem, and a head at one end of the stem, said head having in longitudinal section a contour extending successively from its center along an arch line of the outer head surface toward the outer periphery of the head, and thence toward the other end of the stem along an outer surface line adjacent to said periphery extending precipitately toward the other end of the stem, and including a portion sloping toward said other end of the stem along a line of the valve-seating surface, and thence along a line extending towardsaid outer surface end, and radially inwardly on an inner surface line of the head to the stem, said inner surface line cooperating with said outer arch line to define an arch and cooperating with said precipitate line to define a substantially tubular portion in addition to said arch.

2. An internal combustion engine valve comprising a stem, and a substantially mushroom head at the top of the stem trussed against the forces of the stem and the reactions at the valve seat under the valve-closing action, and having a tubular valve-seating skirt, said head having a top surface portion directed in vertical-plane central section successively from the center of said head at each side thereof along a top surface arch centered in the stem, and extending generally horizontally to a position intermediate the stem axis and the outer periphery of said head, from said position veering from said top surface downwardly on said tubular skirt toward the vertical, along a valve-seating surface sloping downwardly and inwardly toward the stem, and along an arch on the inner surface of said tubular skirt and on the under surface of said head above the top horizontal plane of the valve seat extending into the surface of the stem.

3. An internal combustion engine valve and seat combination, said valve comprising a stem and a mushroom head with a seating portion of substantially tubular form, the seating surface between said valve head and said valve seat comprising conical elements making an obtuse angle with said valve axis and approximately perpendicular to the tubular seating portion of the valve.

4. An internal combustion engine valve and seat combination, said valve comprising a stem and a mushroom head with a seating portion substantially parallel to the valve axis, the seating surface between said valve head and said valve seat comprising conical elements making an obtuse angle with said valve axis and approximately perpendicular to the tubular seating portion of the valve.

5. An internal combustion engine valve and seat combination, said valve comprising a stem and a mushroom head with a seating portion of substantially cylindrical form, the seating surface between said valve head and said valve seat comprising conical elements making an obtuse angle with said valve axis and approximately perpendicular to the tubular seating portion of the valve.

6. An internal combustion engine valve comprising a stem, and a mushroom head trussed against the forces imposed by the stem on the head, and the head on the seat connected at the concave side of the head to one end of the stem, the convex side of the head substantially following an arc of long radius from a point on the valve axis in every plane parallel to, and through the valve axis, and continuing at each end adjacent to the outer periphery of the head along a line making a precipitate turn from said long are toward the other end of the stem, the surface of the stem in each of said planes merging at opposite sides into the surface of the concave side of the head through turns of substantially short bend compared to said long radius, the surface of the concave side of the head in each of said planes adjacent to each end of said'long arc ends also making a precipitate turn into substantial parallelism to said axis whereby, with said first precipitate turn, to form a substantially tubular valveseating skirt extending along the valve axis toward said other end of the stem and having a valve-seating surface convergingly sloped relative to the valve axis toward said other end of the stem substantially at right angles to saidtubular portion, the head thereby being of substantially cup-shape on both its inner and outer surfaces independently of said valve-seating skirt and being connected tothe stem at a position disposed a substantial distance from said valve-seating surface toward said one end of the stem.

CARL E. BERSTLER. 

